1. Field of the Invention
The present invention relates to a pump discharging a very small quantity of a liquid and is applicable to delivery pumps for a soldering paste, a solvent such as alcohol and an adhesive.
2. Description of the Related Art
Heretofore, the so-called chip mounter or the like fixing chips and the like to various substrates mounts the chips to a substrate after applying a soldering paste to the substrate, and then places the resulting chips-mounting substrate in a furnace to fix the chips to the substrate.
In this case, a dispenser pneumatically discharging the paste is known as a device applying the paste to the substrate.
Since, however, this kind of dispenser pneumatically discharges the paste, a flow control is very difficult when a discharge pressure is high, and in particular, the flow control is more difficult because of external disturbances such as lumps in a liquid, the quantity of the liquid in the dispenser, or a change in the viscosity of the liquid due to a temperature.
In addition, a pump which can discharge a liquid in a very small quantity and at a high accuracy for a solvent such as alcohol and an adhesive in addition to a soldering paste has been desired and a pump which can supply a liquid at a high speed has been desired in order to decrease workhours per step.